1. Field of the Invention
The invention relates to a lifting device for setting floating objects such as sea vehicles afloat in the water and raising them.
The invention relates more particularly to a lifting device including a suspended coupling element, adapted to be coupled with the load during the launching or raising operation.
The lifting device of the invention is particularly well adapted to handling boats subjected, because of the swell, to relative movements with respect to the lifting appliances. This is the case more particularly for floating objects, vehicles of low tonnage for example, which must be launched or raised by a lifting system on board a ship.
2. Description of the Prior Art
Lifting devices are known including a coupling element which is suspended by cables to a lifting appliance. This latter is operated for lowering the coupling element until it is brought into a position where one or more hooks secured to the load may be fixed thereto, either directly or by means of cables. The operation is generally impeded by the horizontal or vertical movements of the floating object or vehicle, relatively to the lifting device, under the effect of the swell, which often uncouple the hooks and the coupling element. The operation for seizing the hook or hooks must often be renewed several times. To the handling difficulties and dangers are added the risks of collision in the case where the boat is raised or lowered from a main ship, especially when the sea is rough. The lifting device of the invention overcomes the above mentioned drawbacks.